U.S. patent number 7,597,012 [Application Number 11/454,750] was granted by the patent office on 2009-10-06 for system and method for using a spray/liquid particle count (lpc) to measure particulate contamination.
This patent grant is currently assigned to Hitachi Global Storage Technologies Netherlands B.V.. Invention is credited to Hui Yan Hu, Shaoyong Liu, Kelvin Ang Kor Seng, Garvin J. Stone, Gina M. Whitney, Yi Zhao Yao.
United States Patent |
7,597,012 |
Yao , et al. |
October 6, 2009 |
System and method for using a spray/liquid particle count (LPC) to
measure particulate contamination
Abstract
A system and method for using a spray/liquid particle count
(LPC) to measure particulate contamination is disclosed. Initially,
a component for particulate extraction is received. A sprayer is
provided for spraying a liquid on the component. In addition, a
container is provided for catching the liquid spraying on the
component. The container is clean prior to receiving the liquid and
the liquid is collected for later analysis of a number of particles
extracted from the component.
Inventors: |
Yao; Yi Zhao (Singapore,
SG), Hu; Hui Yan (Singapore, SG), Liu;
Shaoyong (Singapore, SG), Seng; Kelvin Ang Kor
(Singapore, SG), Stone; Garvin J. (San Juan Bautista,
CA), Whitney; Gina M. (San Jose, CA) |
Assignee: |
Hitachi Global Storage Technologies
Netherlands B.V. (Amsterdam, NL)
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Family
ID: |
38860284 |
Appl.
No.: |
11/454,750 |
Filed: |
June 15, 2006 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20070289394 A1 |
Dec 20, 2007 |
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Current U.S.
Class: |
73/863.21 |
Current CPC
Class: |
B08B
3/00 (20130101); G01N 1/04 (20130101); G01N
15/06 (20130101); G01N 2015/0053 (20130101); G01N
2001/028 (20130101); G01N 2001/1006 (20130101) |
Current International
Class: |
G01N
1/22 (20060101) |
Field of
Search: |
;73/863.21,61.71,61.72
;134/18,34,32,57R |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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1025385 |
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Jan 1989 |
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2285635 |
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6258202 |
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Sep 1994 |
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JP |
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8045888 |
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Feb 1996 |
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JP |
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9005227 |
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Jan 1997 |
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JP |
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2002011419 |
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Jan 2002 |
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JP |
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2002025049 |
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Jan 2002 |
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JP |
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Other References
"Contactless Scrubber-A Disk Cleaning Device", IBM Technical
Disclosure Bulletin, (Jan. 1982),p. 4023. cited by other .
"Method of Quantitatively Detecting Particles On Surfaces", IBM
Technical Disclosure Bulletin, (Nov. 1986). cited by other .
"Wafter Cleaner by Use of High Pressure Pulsating Liquid", IBM
Technical Disclosure Bulletin, (Apr. 1978),p. 4331. cited by
other.
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Primary Examiner: Williams; Hezron
Assistant Examiner: Bellamy; Tamiko D
Claims
What is claimed is:
1. A method for using a spray/liquid particle count (LPC) to
measure particulate contamination, said method comprising:
receiving a component from a hard disk drive as said component for
particulate extraction; providing a sprayer for spraying a liquid
on said component; and providing a container for catching said
liquid spraying on said component, wherein said container is clean
prior to receiving said liquid and said liquid is collected for
later analysis of a number of particles extracted from said
component.
2. The method of claim 1 wherein said sprayer further comprises:
utilizing a nozzle providing a full cone spray pattern for spraying
said liquid on said component.
3. The method of claim 1 wherein said sprayer further comprises:
utilizing a nozzle providing a flat fan spray pattern for spraying
said liquid on said component.
4. The method of claim 1 further comprising: utilizing distilled
water as said liquid for spraying on said component.
5. The method of claim 4 further comprising: providing
approximately a 0.004% micro 90 detergent to said distilled water
for spraying on said component.
6. The method of claim 1 wherein further comprising: utilizing
approximately a 25 degree angle of spray between said sprayer and
said component for particulate extraction.
7. The method of claim 1 further comprising: utilizing
approximately a 1 inch standoff between said sprayer and said
component for particulate extraction.
8. The method of claim 1 further comprising: utilizing
approximately a 65 milliliter per minute flow rate at approximately
a 40 pounds per square inch pressure.
9. The method of claim 1 further comprising: utilizing a beaker as
said container for catching said liquid spraying on said
component.
10. A spray/liquid particle count (LPC) component particulate
extractor for extracting particulate from a component of a hard
disk drive comprising: a retaining mechanism for receiving a hard
disk drive component for particulate extraction; a sprayer for
providing a stream of spraying liquid to said hard disk drive
component; and a container for catching said liquid spraying on
said hard disk drive component, wherein said container is clean
prior to receiving said liquid, wherein said liquid is provided to
an LPC analyzer for counting a number of particles extracted from
said hard disk drive component.
11. The spray/LPC component particulate extractor of claim 10
wherein said stream of spraying liquid sprayed from said sprayer is
received from a pressurized container.
12. The spray/LPC component particulate extractor of claim 10
wherein said sprayer utilizes a nozzle providing a full cone spray
pattern for spraying said liquid on said component.
13. The spray/LPC component particulate extractor of claim 10
wherein said sprayer utilizes a nozzle providing a flat fan spray
pattern for spraying said liquid on said component.
14. The spray/LPC component particulate extractor of claim 10
wherein distilled water is utilized as said liquid for spraying on
said component.
15. The spray/LPC component particulate extractor of claim 14
wherein approximately a 0.004% micro 90 detergent is provided to
said distilled water for spraying on said component.
16. The spray/LPC component particulate extractor of claim 10
wherein said sprayer comprises: an approximate 25 degree angle of
spray between said sprayer and said component for particulate
extraction; and an approximately 1 inch standoff between said
sprayer and said component for particulate extraction.
17. The spray/LPC component particulate extractor of claim 16
wherein said sprayer further comprises: an approximately 65
milliliter per minute flow rate at approximately a 40 pounds per
square inch pressure is utilized.
18. The spray/LPC component particulate extractor of claim 10
further comprising: utilizing a beaker as said container for
catching said liquid spraying on said component.
Description
TECHNICAL FIELD
The present invention relates generally to particulate
contamination measurement, and more particularly to a system and
method for using a spray/liquid particle count (LPC) to measure
particulate contamination.
BACKGROUND ART
Hard disk drives are used in almost all computer system operations.
In fact, most computing systems are not operational without some
type of hard disk drive to store the most basic computing
information such as the boot operation, the operating system, the
applications, and the like. In general, the hard disk drive is a
device which may or may not be removable, but without which the
computing system will generally not operate.
The basic hard disk drive model includes a storage disk or hard
disk that spins at a designed rotational speed. An actuator arm is
utilized to reach out over the disk. The arm carries a head
assembly that has a magnetic read/write transducer or head for
reading/writing information to or from a location on the disk. The
transducer is attached to a slider, such as an air-bearing slider,
which is supported adjacent to the data surface of the disk by a
cushion of air generated by the rotating disk. The transducer can
also be attached to a contact-recording type slider. In either
case, the slider is connected to the actuator arm by means of a
suspension. The complete head assembly, e.g., the suspension and
head, is called a head gimbal assembly (HGA).
In operation, the hard disk is rotated at a set speed via a spindle
motor assembly having a central drive hub. Additionally, there are
tracks evenly spaced at known intervals across the disk. When a
request for a read of a specific portion or track is received, the
hard disk aligns the head, via the arm, over the specific track
location and the head reads the information from the disk. In the
same manner, when a request for a write of a specific portion or
track is received, the hard disk aligns the head, via the arm, over
the specific track location and the head writes the information to
the disk.
Over the years, the disk and the head have undergone great
reductions in their size. Much of the refinement has been driven by
consumer demand for smaller and more portable hard drives such as
those used in personal digital assistants (PDAs), MP3 players, and
the like. For example, the original hard disk drive had a disk
diameter of 24 inches. Modern hard disk drives are much smaller and
include disk diameters of less than 2.5 inches (micro drives are
significantly smaller than that). Advances in magnetic recording
are also primary reasons for the reduction in size.
This continual reduction in size has placed steadily increasing
demands on the technology used in extracting particulate from the
hard disk drive and the components thereof. For example,
particulate contamination has been one of the major contaminations
encountered in HDD (Hard Disk Drive) industries, on its components,
in its assembly processes.
Presently, as shown in background FIG. 1a, US/LPC (Ultrasonic
Extraction/Liquid Particle Count) is a well established LPC method
for extracting particulates from components of a HDD. Moreover,
US/LPC has been widely used in HDD industries for many years.
In general, the US/LPC 100 method includes providing a tank 120
with a liquid 125 therein. A container 105, filled with an amount
of extracting liquid 115 and the component 110, is placed into the
tank 120. Ultrasonic energy is then provided to the liquid 125 in
tank 120. The ultrasonic energy transfers through the liquid 125
and into the extracting liquid 115 in container 105. The component
110 is ultrasonically extracted and the extracting liquid 115
receives the removed particles. The particle filled liquid 115 is
then taken for LPC. The particle sized detected can be 2 um, 0.5
um, 0.3 um or 0.2 um, or smaller; and the Ultrasonic Frequency
commonly used can be one of the following: 40, 68, 80, 120, 132,
140, 170, 192, 220, 270 kHz, or even high frequencies.
However, the ultrasonic extraction method is extremely stressful on
the component 110 during the extraction process. That is, the
number of particles that are found after extracting, via the LPC,
is high and is mainly due to the ultrasonic energy eroding
connected base material, rather than removing loose particles, from
the component 110.
For example, FIG. 1b provides a graph of particles found after
ultrasonically extracting a component 160 without a scratch and an
equivalent component 170 with 4 lines of scratches. From the graph
150, it is apparent that there is no significant deviation between
the two components 160 and 170. In other words, the component 160
with no scratches provides a statistically similar number of
particles as the component 170 with four lines of scratches.
Therefore, what is needed is a gentle extraction method for
utilization on HDD components, subassemblies, whole drive,
tools/jigs, HDD consumables, and any other non HDD items which
require particle extracting.
SUMMARY
A system and method for using a spray/liquid particle count (LPC)
to extract particulate from a component is disclosed. Initially, a
component for particulate extraction is received. A sprayer is
provided for spraying a liquid on the component. In addition, a
container is provided for catching the liquid spraying on the
component. The container is clean prior to receiving the liquid and
the liquid is collected for later analysis of a number of particles
extracted from the component
BRIEF DESCRIPTION OF THE DRAWINGS
Background FIG. 1a is an exemplary block diagram of a US/LPC
(Ultrasonic Extraction/Liquid Particle Count) apparatus.
Background FIG. 1b is a graph of two components with a different
number of scratches with particulate extracted via a US/LPC
apparatus.
FIG. 2 is a plan view of an HDD with cover and top magnet removed
in accordance with one embodiment of the present invention.
FIG. 3 is an exemplary block diagram of a Spray/LPC apparatus in
accordance with one embodiment of the present invention.
FIG. 4 is a graph of four similar components with a different
number of scratches per component and the resulting particulate
extraction realized when utilizing a spray/LPC apparatus in
accordance with one embodiment of the present invention.
FIG. 5a is an exemplary flat fan spray pattern in accordance with
one embodiment of the present invention.
FIG. 5b is an exemplary conical spray pattern in accordance with
one embodiment of the present invention.
FIG. 6 is a flowchart of an exemplary method for using a
spray/liquid particle count (LPC) to extract particulate from a
component in accordance with one embodiment of the present
invention.
DETAILED DESCRIPTION
Reference will now be made in detail to the alternative
embodiment(s) of the present invention. While the invention will be
described in conjunction with the alternative embodiment(s), it
will be understood that they are not intended to limit the
invention to these embodiments. On the contrary, the invention is
intended to cover alternatives, modifications and equivalents,
which may be included within the spirit and scope of the invention
as defined by the appended claims.
Furthermore, in the following detailed description of the present
invention, numerous specific details are set forth in order to
provide a thorough understanding of the present invention. However,
it will be recognized by one of ordinary skill in the art that the
present invention may be practiced without these specific details.
In other instances, well known methods, procedures, and components
have not been described in detail as not to unnecessarily obscure
aspects of the present invention.
The discussion will begin with an overview of a hard disk drive and
components connected therewith. The discussion will then focus on a
physical description of the spray/liquid particle count (LPC)
component particulate extractor apparatus. Finally, an exemplary
method for using a spray/liquid particle count (LPC) to measure
particulate contamination will be described.
The method will provide a spray/LPC system that is able to
sensitively detect and remove surface loose particles on a
component without removing significant amounts of attached base
components. In other words, the spray/LCP method and system
described herein will extract loose particles without significantly
removing attached particles from the components. As is well known,
the most harmful particles, e.g., particles that will detrimentally
effect overall operation of an assembly using the component, are
the loose particles.
Overview
With reference now to FIG. 2, a plan view of an HDD with cover and
top magnet removed is shown in accordance with one embodiment of
the present invention. FIG. 2 illustrates the relationship of
components and sub-assemblies of HDD 210 and a representation of
data tracks 236 recorded on the disk surfaces 235 (one shown). The
cover is removed and not shown so that the inside of HDD 210 is
visible. The components are assembled into base casting 213, which
provides attachment and registration points for components and
sub-assemblies.
A plurality of suspension assemblies 237 (one shown) are attached
to the actuator arms 234 (one shown) in the form of a comb. A
plurality of transducer heads or sliders 255 (one shown) are
attached respectively to the suspension assemblies 237. Sliders 255
are located proximate to the disk surfaces 235 for reading and
writing data with magnetic heads 256 (one shown). The rotary voice
coil motor 250 rotates actuator arms 234 about the actuator shaft
232 in order to move the suspension assemblies 237 to the desired
radial position on disks 212. The actuator shaft 232, hub 240,
actuator arms 234, and voice coil motor 250 may be referred to
collectively as a rotary actuator assembly.
Data is recorded onto disk surfaces 235 in a pattern of concentric
rings known as data tracks 236. Disk surface 235 is spun at high
speed by means of a motor-hub assembly 230. Data tracks 236 are
recorded onto spinning disk surfaces 235 by means of magnetic heads
256, which typically reside at the end of sliders 255. FIG. 2 being
a plan view shows only one head, slider, and disk surface
combination. One skilled in the art understands that what is
described for one head-disk combination applies to multiple
head-disk combinations, such as disk stacks (not shown). However,
for purposes of brevity and clarity, FIG. 2 only shows one head and
one disk surface.
Referring now to FIG. 3, an exemplary block diagram of a Spray/LPC
apparatus 300 is shown in accordance with one embodiment of the
present invention. In one embodiment, spray/LPC 300 includes an arm
305 for supporting a component 310 over a container 320. In
addition, spray/LPC 300 includes a sprayer 315, a pressurized
container 365, and fluid 325 which is the fluid collected after
being sprayed on component 310 from sprayer 315. Spray/LPC also
illustrates an adjustable angle of spray 330 and an adjustable
standoff distance 335.
With reference now to FIG. 4, a graph 400 of four similar
components with a different number of scratches per component and
the resulting particulate extraction realized when utilizing a
spray/LPC apparatus 300 is shown in accordance with one embodiment
of the present invention. Specifically, graph 400 provides a first
component 410 with no scratches, a second component 420 with one
scratch line, a third component 430 with two lines of scratches and
a fourth component 440 with 4 lines of scratches. As is clearly
shown, the graph 400 includes two samples and an average for each
of the four test cases.
At graph 400, a linear relationship can be clearly seen between the
four distinct scratch cases. This spray/LPC linear relationship is
in direct contrast to graph 150, of FIG. 1b, where the ultrasonic
extractor provided no significant statistical difference between a
component 160 with no scratches and a component 170 with four
scratches.
Not only does the graph 400 provide a linear relationship based on
the number of scratches (e.g., number of loose particles) but the
graph 400 also shows a significant reduction in the overall number
of particles removed from the components. For example, in graph
150, the component with no scratches provided an average 1,135,370
particles after ultrasonic extracting. However, in graph 400, the
worst case 4 scratch average was only 98,706 particles after spray
extracting. This is a difference of over one million particles.
Thus, graph 400 in comparison with graph 150 clearly illustrates
that the spray/LPC method described herein significantly reduces
the wear on the components. That is, unlike ultrasonic extracting,
the spray extracting does not significantly degrade the component.
Additionally, the spray/LPC extracting does not significantly
remove base particles still connected to the component. Instead,
the spray/LPC extracting removes loose particles in a linear and
repeatable fashion.
Referring now to FIG. 5a, an exemplary flat fan spray pattern 500
is shown in accordance with one embodiment of the present
invention. With reference now to FIG. 5b, an exemplary conical
spray pattern 550 is shown in accordance with one embodiment of the
present invention. The details of the spray patterns including
pattern 500 and 550 are described in more detail herein. Moreover,
they are provided herein merely for purposes of brevity and
clarity. They are not meant to infer that they are the only
available spray patterns.
Referring now to FIG. 6 and to FIG. 3, a flowchart 600 of an
exemplary method for using a spray/liquid particle count (LPC)
apparatus 300 to extract particulate and measure particulate
contamination of a component is shown in accordance with one
embodiment of the present invention. In general, the spray/LPC 300
extraction described herein is used to sensitively detect and
remove particulate contamination or quality problems such as
scratches, burrs, improper handling, and the like. This extracting
results in loose particles being sensitively removed from the
component 310 without aggressively over extracting particulate from
the component 310.
With reference now to 602 of FIG. 6 and to FIG. 3, one embodiment
receives a component 310. In one embodiment, the component 310 is a
component in a hard disk drive (HDD). However, in another
embodiment, the component 310 is a HDD subassembly, an entire HDD,
a tool or jig associated with a HDD, and HDD consumables. In yet
another embodiment, the component 310 is not associated with a HDD.
For example, the component 310 may be a component from the
semiconductor industry, or the like. As shown in FIG. 3, the
component 310 is supported in the proper position within the
spray/LPC apparatus 300 by the supporting arm 305.
Referring now to 604 of FIG. 6 and to FIG. 3, one embodiment
provides a sprayer 315 for spraying a liquid 325 on the component
310. The sprayer 315 may be any of a number or liquid spraying
systems. For example, in FIG. 3, the sprayer 315 is connected to a
pressurized tank 365 to form the spraying system. However, it is
understood that the spraying system can be any of a plurality of
spraying methods such as a pressurized system, a gravity fed
system, and the like. The use of a pressurized system is described
herein merely for purposes of brevity and clarity.
In one embodiment, the sprayer 315 includes a nozzle having a full
cone spray pattern 550, as shown in FIG. 5b, for spraying the
liquid 325 on the component 310. In another embodiment, the sprayer
315 includes a nozzle having a flat fan spray pattern 500, as shown
in FIG. 5a, for spraying the liquid 325 on the component 310.
Although two spray patterns are described, it is understood that
the provided patterns are exemplary. That is, the present invention
is well suited to a plurality of spray patterns. The use of the
approximate numbers provided herein is merely for purposes of
brevity and clarity.
For example, tables 1, 2 and 3 provide an overview of the spray
nozzle impact characteristics.
TABLE-US-00001 TABLE 1 for a fixed nozzle, impact is proportional
to the liquid pressure or spray flowrate. Spray/LPC (>2 um
Spray/LPC (>=2 um per part) @ 40 psi per part) @ 60 psi Impact @
60 psi Vs Component Nozzle (350 ml/mm) (440 ml/mm) Impact @ 40 psi
Part A 6501 Flat Fan Spray 9916 12507 9297 12004 10024 Avg 9747
12256 26% higher
TABLE-US-00002 TABLE 2 for different capacity but same type of
nozzles, impact is not a function of spray flowrate. Spray/LPC
(>2 um per Spray/LPC (>=2 um per part) by 6501 part) by
3404K643 Impact @ 3404K643 Vs Component Nozzle (440 ml/mm @ 60 psi)
(1600 m1/min @ 60 psi) Impact @ 6501 Part A 6501 Flat Vs 12507 9125
3404K643 Flat 12004 7950 Avg 12256 8538 30% lower
TABLE-US-00003 TABLE 3 for different types of nozzles, impact is
not a function of spray flowrate. Spray/LPC (>2 um per Spray/LPC
(>=2 um per part) by 6501 (350 mi/mm part) by M6 (350 mi/mm
Impact @ M6 Vs Component Nozzle @ 40 psi) @ 40 psi) Impact @ 6501
Part A 6501 Flat 10757 7115 Vs M6 Fine 9752 7154 10238 7202 10249
7157 30% lower
In one embodiment, the sprayer 315 sprays distilled water on the
component 310. That is, only distilled water is sprayed from the
sprayer 315 onto the component 310. In another embodiment,
approximately a 0.004% micro 90 detergent is provided to the
distilled water for spraying on the component 310. The detergent is
utilized to aid in extracting particulate from a component 310.
Although an approximate detergent mix is described herein, it is
understood that the provided percentage is exemplary. That is, the
present invention is well suited to a plurality of detergent mixes.
The use of the approximate number provided herein is merely for
purposes of brevity and clarity.
For example, table 4 provides an overview of the effects of
detergent and its concentration on the impact of a nozzle.
TABLE-US-00004 TABLE 4 Spray/LPC (>2 um Nozzle and Spray
Condition Part per part) of Component B 250017 Flat Fan spray Part
#1 6435 @ 4 opsi Pure DIW Part #2 5562 Average 250017 Flat Fan
spray Part #1 7526 @ 4 opsi 0.004% Detergent Part #2 6722 Average
7124 250017 Flat Fan spray Part #1 12849 @ 4 opsi 0.04% Detergent
Part #2 13245 Average 13047
Although detergent can help enhance the nozzle's spray impact, high
concentrations of detergent may cause unwanted air bubbles.
Therefore, in one embodiment, a very low level of detergent is
utilized to enhance the particle removal from the component's
surface.
The sprayer also utilizes approximately a 25 degree angle of spray
330 between the sprayer and the component, in one exemplary
embodiment. In another embodiment, approximately a one inch
standoff 335 is utilized between the sprayer 315 and the component
310 receiving the particle extraction. In yet another embodiment,
approximately a 65 milliliter per minute flow rate at approximately
40 pounds per square inch pressure is utilized. Although an angle
of spray 330, standoff 335 and pressure are provided herein, it is
understood that the provided numbers are exemplary. That is, the
present invention is well suited to a plurality of pressures,
angles and standoffs alone and in combination as shown in the
following tables based on spray pattern, component being extracted,
use of detergent, and the like. The use of the approximate numbers
herein is merely exemplary embodiments provided for purposes of
brevity and clarity.
For example, table 5 provides an overview of the effect of
different praying distances (>=2 um per part).
TABLE-US-00005 TABLE 5 Spraying Part Distance Name Part #1 Part #2
Part #3 Part #4 Part #5 Average Std Dev 15 mm Part C 4792 4922 5172
5263 5287 5087 219 25 mm = 1 inch Part C 3861 4316 4418 4463 4623
4336 288 15 vs. 25 mm 19% 12% 15% 15% 13% 15% Particle
Reduction
Referring now to 606 of FIG. 6 and to FIG. 3, one embodiment
provides a container 320 for catching the liquid 325 spraying on
the component, wherein the container 320 is clean prior to
receiving the liquid 325 and the liquid is collected for later
analysis of a number of particles extracted from the component 310.
In one embodiment, a beaker is used as the container 320 for
catching the liquid 325 sprayed on the component 310.
For example, in one exemplary embodiment, the sprayer 315 sprays
liquid 325 onto component 310 for 1-3 minutes depending on the
size, surface area, complexity of parts or subassemblies, and the
like. After the spraying is stopped and the particles on the
component 310 have been extracted, the fluid 325 collected in the
container 320 is then processed by a LPC to establish the particle
count. That is, the particles washed from component 310 are counted
by performing a particle count on the now contaminated liquid
325.
Thus, embodiments of the present invention provide a system and
method for using a spray/liquid particle count (LPC) to measure
particulate contamination. Moreover, embodiments provide a system
and method for using a spray/liquid particle count (LPC) to measure
particulate contamination that significantly reduces the number of
attached particles being unnecessarily removed from the component.
Additionally, embodiments provide a system and method for using a
spray/liquid particle count (LPC) to measure particulate
contamination that significantly protects the component from damage
during the extraction process. In so doing, particulate from the
component is more quickly, efficiently, and properly extracted
while deleterious over extracting effects, such as extracting
damage or stresses on the component are reduced.
While the method of the embodiment illustrated in flowchart 600
show specific sequences and quantity of steps, the present
invention is suitable to alternative embodiments. For example, not
all the steps provided for in the methods are required for the
present invention. Furthermore, additional steps can be added to
the steps presented in the present embodiment. Likewise, the
sequences of steps can be modified depending upon the
application.
The alternative embodiment(s) of the present invention, a system
and method for using a spray/liquid particle count (LPC) to measure
particulate contamination is thus described. While the present
invention has been described in particular embodiments, it should
be appreciated that the present invention should not be construed
as limited by such embodiments, but rather construed according to
the below claims.
* * * * *